Delayed simvastatin treatment improves neurological recovery after cryogenic traumatic brain injury through downregulation of ELOVL1 by inhibiting mTOR signaling.

Statins are well-tolerated and widely available lipid-lowering medications with neuroprotective effects against traumatic brain injury (TBI). However, whether delayed statin therapy starting in the subacute phase promotes recovery after TBI is unknown. Elongation of the very long-chain fatty acid protein 1 (ELOVL1) is involved in astrocyte-mediated neurotoxicity, but its role in TBI and the relationship between ELOVL1 and statins are unclear. We hypothesized that delayed simvastatin treatment promotes neurological functional recovery after TBI by regulating the ELOVL1-mediated production of very long-chain fatty acids (VLCFAs). ICR male mice received daily intragastric administration of 1, 2 or 5mg/kg simvastatin on Days 1-14, 3-14, 5-14, or 7-14 after cryogenic TBI (cTBI). The results showed that simvastatin promoted motor functional recovery in a dose-dependent manner, with a wide therapeutic window of at least 7 days postinjury. Meanwhile, simvastatin inhibited astrocyte and microglial overactivation and glial scar formation, and increased total dendritic length, neuronal complexity and spine density on day 14 after cTBI. The up-regulation of ELOVL1 expression and saturated VLCFAs concentrations in the cortex surrounding the lesion caused by cTBI was inhibited by simvastatin, which was related to the inhibition of the mTOR signaling. Overexpression of ELOVL1 in astrocytes surrounding the lesion using HBAAV2/9-GFAP-m-ELOVL1-3xFlag-EGFP partially attenuated the benefits of simvastatin. These results showed that delayed simvastatin treatment promoted functional recovery and brain tissue repair after TBI through the downregulation of ELOVL1 expression by inhibiting mTOR signaling. Astrocytic ELOVL1 may be a potential target for rehabilitation after TBI.

Targeting Neuronal GPR65 With Delayed BTB09089 Treatment Improves Neurorehabilitation Following Ischemic Stroke.

BACKGROUND: GPR65 (G protein-coupled receptor 65) can sense extracellular acidic environment to regulate pathophysiological processes. Pretreatment with the GPR65 agonist BTB09089 has been proven to produce neuroprotection in acute ischemic stroke. However, whether delayed BTB09089 treatment and neuronal GPR65 activation promote neurorestoration remains unknown. METHODS: Ischemic stroke was induced in wild-type (WT) or GPR65 knockout (GPR65-/-) mice by photothrombotic ischemia. Male mice were injected intraperitoneally with BTB09089 every other day at days 3, 7, or 14 poststroke. AAV-Syn-GPR65 (adenoassociated virus-synapsin-GPR65) was utilized to overexpress GPR65 in the peri-infarct cortical neurons of GPR65-/- and WT mice. Motor function was monitored by grid-walk and cylinder tests. The neurorestorative effects of BTB09089 were observed by immunohistochemistry, Golgi-Cox staining, and Western blotting. RESULTS: BTB09089 significantly promoted motor outcomes in WT but not in GPR65-/- mice, even when BTB09089 was delayed for 3 to 7 days. BTB09089 inhibited the activation of microglia and glial scar progression in WT but not in GPR65-/- mice. Meanwhile, BTB09089 reduced the decrease in neuronal density in WT mice, but this benefit was abolished in GPR65-/- mice and reemerged by overexpressing GPR65 in peri-infarct cortical neurons. Furthermore, BTB09089 increased the GAP43 (growth-associated protein-43) and synaptophysin puncta density, dendritic spine density, dendritic branch length, and dendritic complexity by overexpressing GPR65 in the peri-infarct cortical neurons of GPR65-/- mice, which was accompanied by increased levels of p-CREB (phosphorylated cAMP-responsive element-binding protein). In addition, the therapeutic window of BTB09089 was extended to day 14 by overexpressing GPR65 in the peri-infarct cortical neurons of WT mice. CONCLUSIONS: Our findings indicated that delayed BTB09089 treatment improved neurological functional recovery and brain tissue repair poststroke through activating neuronal GRP65. GPR65 overexpression may be a potential strategy to expand the therapeutic time window of GPR65 agonists for neurorehabilitation after ischemic stroke.

Targeting astrocytic TDAG8 with delayed CO2 postconditioning improves functional outcomes after controlled cortical impact injury in mice.

T-cell death-associated gene 8 (TDAG8), a G-protein-coupled receptor sensing physiological or weak acids, regulates inflammatory responses. However, its role in traumatic brain injury (TBI) remains unknown. Our recent study showed that delayed CO2 postconditioning (DCPC) has neuroreparative effects after TBI. We hypothesized that activating astrocytic TDAG8 is a key mechanism for DCPC. WT and TDAG8-/- mice received DCPC daily by transiently inhaling 10% CO2 after controlled cortical impact (CCI). HBAAV2/9-GFAP-m-TDAG8-3xflag-EGFP was used to overexpress TDAG8 in astrocytes. The beam walking test, mNSS, immunofluorescence and Golgi-Cox staining were used to evaluate motor function, glial activation and dendritic plasticity. DCPC significantly improved motor function; increased total dendritic length, neuronal complexity and spine density; inhibited overactivation of astrocytes and microglia; and promoted the expression of astrocytic brain-derived neurotrophic factor in WT but not TDAG8-/- mice. Overexpressing TDAG8 in astrocytes surrounding the lesion in TDAG8-/- mice restored the beneficial effects of DCPC. Although the effects of DCPC on Days 14-28 were much weaker than those of DCPC on Days 3-28 in WT mice, these effects were further enhanced by overexpressing astrocytic TDAG8. Astrocytic TDAG8 is a key target of DCPC for TBI rehabilitation. Its overexpression is a strategy that broadens the therapeutic window and enhances the effects of DCPC.

[Anti-inflammatory mechanism of Crepis crocea based on NF-κB signaling pathway and ~1H-NMR metabonomics].

Based on ~1H-NMR metabonomics technique and Western blot assay, the anti-inflammatory mechanism of Crepis crocea was discussed. In this study, male SD rats were treated with water extract(2.5 g·kg~(-1)) and dexamethasone acetate(6.25×10~(-4) g·kg~(-1)) for one week, and the inflammation model was induced by lipopolysaccharide(LPS). Then the counts of inflammatory cells white blood ceel(WBC), eosinophil(EO), lymphocyte(LY), basophils(BA) and neutrophils(NE) in whole blood of rats were observed. The levels of serum inflammatory factors tumor necrosis factor-α(TNF-α), interleukin-1ß(IL-1ß), IL-6 and the expression of nuclear factor-κB(NF-κB) signaling pathway p65 and p-IκBα proteins in lung tissues were detected, and the change rules of serum endogenous metabolites were analyzed by ~1H-NMR metabonomics technique. The levels of TNF-α, IL-1ß, IL-6 and NF-κB signaling pathway p65 and p-IκBα proteins were combined with ~1H-NMR metabonomics to study the anti-inflammatory mechanism of C. crocea. The results showed that the water extract of C. crocea significantly decreased the number of WBC, NE, EO, increased the number of BA and LY, decreased the levels of TNF-α, IL-1ß, IL-6 and the expression of p65 and p-IκBα protein in NF-κB signaling pathway, and effectively alleviated the inflammatory symptoms. In the correlation analysis of differential metabolites regulated of C. crocea, four significant metabolites were obtained, including glycine, creatine, methionine and succinic acid. The anti-inflammatory mechanism of C. crocea may be related to the decrease of TNF-α, IL-1ß, IL-6 levels and the protein expression of NF-κB signaling pathway, as well as the regulation of glycine, creatine, methionine and succinic acid metabolism.

[Analysis of chemical components of Huanbei Zhike Prescription based on UPLC-Q-TOF-MS/MS technology].

To characterize the chemical constituents of Huanbei Zhike Prescription by ultra-high performance liquid chromatography-time of flight mass spectrometry( UPLC-Q-TOF-MS/MS). A Thermo Syncronls C18 column( 2. 1 mm×100 mm,1. 7 µm) was used with methanol( A)-0. 1% formic acid solution( B) as the mobile phase for gradient elution. The injection volume was 2 µL; the column temperature was 40 ℃; the flow rate was 0. 3 m L·min-1; and electrospray ionization( ESI) source was used to collect data in positive and negative ion modes. The ion scanning range was m/z 50-1 200,with capillary voltage of 3 000 V,ion source temperature of100 ℃,atomization gas flow rate of 50 L·h-1,desolvent gas flow rate of 800 L·h-1,desolvent temperature of 400 ℃,cone hole voltage of 40 V,with argon as the collision gas and the collision energy was 20-35 V. The excimer ion peak information was analyzed by Waters UNIFI data processing software. The molecular formula with error within 1×10-5 was compared with the data in database to identify the compounds. The secondary fragment ion information of the target compound was selected,and then compared with the retention time and fragmentation patterns provided by the database and the existing literature to further confirm the compositions and structures of the compounds. A total of 68 main compounds in Huanbei Zhike Prescription were identified,including 38 flavonoids,10 organic acids,6 terpenoids and 10 nitrogen-containing compounds,of which 12 compounds were verified by the control substances. This method is rapid and accurate,which provides a new strategy for the qualitative analysis of the chemical constituents of Huanbei Zhike Prescription,and lays a foundation for the further study and quality control of the compound pharmacodynamic substance.